How to allow / workaround nested composite Gradle builds

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I'm running into the same issue as reported here:

I have a Java project A which depends on project B (module), and project B dependes on project C (another module). For project A I would like to setup "includeBuild ../projectB" and for project B I would like too setup "includeBuild ../projectC" so that I could develop everything in Eclipse + Buildship 2.0 without the need to run Gradle for every small change in each of the projecta A, B and C.

But if I setup this I get: "Included build '%s' cannot have included builds.".

Expected Behavior

Recursive "includeBuild" would recursively include dependent projects.

Current Behavior

I get "Included build '%s' cannot have included builds.".

Your Environment

Gradle 3.5, Buildship 2.0, Eclipse 3.6

How can I resolve / work around this issue? In my instance, I have utility project that includes email functionality (using JavaMail). The email functionality is needed in the data project and a UI project. The UI project also depends on the data project.

2 Answers

Adding another answer for a different approach...

Each settings.gradle could add a check to before includeBuild to see if it's already inside a composite. If it's already inside a composite, it doesn't includeBuild.

See here for extra info on the composite check

Eg

project2/settings.gradle

boolean inComposite = gradle.parent != null
if (!inComposite) {
    includeBuild '../project1'
}

project3/settings.gradle

boolean inComposite = gradle.parent != null
if (!inComposite) {
    includeBuild '../project1'
    includeBuild '../project2'
}

project4/settings.gradle

boolean inComposite = gradle.parent != null
if (!inComposite) {
    includeBuild '../project1'
    includeBuild '../project2'
    includeBuild '../project3'
}

etc etc

Using this approach you could run gradle from wherever you like and it should behave as expected (ie substitute dependencies with local projects)

Have you considered

  1. Ensuring that none of the individual builds are composite builds
  2. Having an "uber" build which is a composite of everything

Note that the settings.gradle is itself a groovy script, so you could create a dynamic composite, eg all sub-folders with a build.gradle under a parent.

uber/settings.gradle

new File("c:/someFolder").listFiles().each { File f ->
    if (f.directory && new File(f, 'build.gradle').exists()) {
        includeBuild f
    }
}

Eg

c:/someFolder/project1/build.gradle
c:/someFolder/project1/src/main/java/**/*.java
c:/someFolder/project2/build.gradle
c:/someFolder/project2/src/main/java/**/*.java
c:/uber/settings.gradle (as above)
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